Accurate temperature measurement for semiconductor applications

ABSTRACT

A temperature sensing component enables accurate in situ temperature measurement. The temperature sensing component is disposed within the process chamber. The temperature sensing component has a cavity, in which a transparent cover is disposed over an opening of the cavity. A material is disposed within the cavity of the temperature sensing component, and a sensor is configured to sense a phase change of the material through the transparent cover.

BACKGROUND

In the fabrication of semiconductors there is a need to control theprocess parameters to ensure process consistency and repeatability. Theneed for process control is becoming more important as semiconductordevices are requiring sub-nanometer accuracy in dimension tolerance(e.g., CD, thickness, etch rate, uniformity, profile, etc.) as devicenodes advance to smaller and smaller features (e.g., 90 nm and smaller).In the more advanced processes, feature size variations and dimensionaltolerance in the fabricated device (within a wafer, wafer-to-wafer,lot-to-lot, die-to-die, chamber-to-chamber, etc.) resulting from allprocess variations are required to be smaller than 5 nm and withinthree-sigma of standard deviation. Soon, as wafer processing become evenmore advanced, the allowable feature size variations will be evensmaller, e.g., smaller than 2 nm and within three-sigma of standarddeviation.

One of the more difficult process parameters to control, maintain, andcharacterize is the process temperature. For example, the processtemperature on chamber interior wall surfaces, the substrate supportsurface, and the substrate surface are difficult to control, maintain,and characterize. As discussed within the scope of the presentinvention, the reference to wafers and substrates is interchangeablesince those of ordinary skill in semiconductor fabrication ofteninterchangeably use both terms. Many process recipes are sensitive toprocess temperature variation. Temperature variation as small as 1degree Celsius can have significant effect on the outcome of the processrecipe. For example, in a semiconductor fabrication etch process, polygate CD (critical dimension) can change by as much as 1 nm per 1 degreeCelsius variation in the process temperature, e.g., the temperature onthe surface of a substrate support, the surface of the substrate, etc.Some process recipes can be affected by even smaller variations, e.g.,0.5 degree Celsius, in the process temperature. Accordingly, accuratetemperature control and measurement are becoming critical processcontrol requirements as device nodes advance to smaller and smallerfeature size. Therefore, accurate temperature measurement andcharacterization capable of measuring absolute temperature and sensingsmall temperature changes, e.g., changes as small as 0.5 degree Celsiusor smaller, is desired.

Many of the currently available temperature measurement techniques haveperformance limitations and undesirable effects. For example, many ofthe currently available temperature measurement techniques are unable tomeasure the in situ process temperature accurately. The techniques thathave the capability to measure the in situ process temperature of awafer usually include placing a special wafer with temperature sensorsembedded on the wafer. Placing a special wafer in the process chamberrequires interrupting the normal flow of processing. Usually, placing aspecial wafer into the process chamber requires venting the processchamber to ambient pressure. Once the process chamber is vented,considerable amount of time is required to bring the chamber back toprocess operating conditions (e.g., pressure, temperature, etc.), whichaffects the throughput of lot processing. Also, in many cases, theembedded sensors could be a source of contamination that may causedevice defects. In addition, these special wafers with embedded sensorsare expensive and the sensors are typically not very robust. When thesensors are exposed to process operating conditions, they could fail orwork improperly. Furthermore, the embedded sensors are not acceptablefor delivering the desired measurement accuracy as most of these sensorshave a temperature measurement uncertainty of 0.5 degree Celsius ormore. Thus, an improved in situ temperature measurement method andapparatus are needed.

SUMMARY

Broadly speaking, the present invention provides the methods andstructures that enable accurate in situ temperature measurement.

In one embodiment, a process chamber with a temperature sensingcomponent enabling accurate in situ temperature measurement is provided.In this embodiment, the temperature sensing component is disposed withinthe process chamber. The temperature sensing component has a cavity, inwhich a transparent cover is disposed over an opening of the cavity. Amaterial is disposed within the cavity of the temperature sensingcomponent, and a sensor is configured to sense a phase change of thematerial through the transparent cover.

In another embodiment, another process chamber with a temperaturesensing component enabling accurate in situ temperature measurement isprovided. In this embodiment, the temperature sensing component isdisposed on a surface within the process chamber (e.g., an interiorsurface of a process chamber, surface on a substrate support, etc). Thetemperature sensing component has a cavity. A material is disposedwithin the cavity of the temperature sensing component, wherein thematerial is in contact with the surface within the process chamber. Asensor is configured to sense a phase change of the material.

In yet another embodiment, a method for accurate in situ temperaturemeasurement is provided. The method includes placing a temperaturesensing component within a process chamber. The temperature sensingcomponent having an embedded material. Then, a process operation isinitiated within the process chamber. After a certain amount of time,the process operation will cause a phase change of the embeddedmaterial. The phase change of the embedded material is then detected. Atemperature associated with the phase change is recorded.

Other aspects and advantages of the present invention will becomeapparent from the following description, taken in conjunction with theaccompanying drawings, illustrating by way of examples the principles ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings, andlike reference numerals designating like structural elements.

FIG. 1 is a cross-sectional diagram of a process chamber havingtemperature sensing components disposed therein, in accordance with oneembodiment of the present invention.

FIG. 2 is a close-up cross-sectional view of a portion of thetemperature sensing component, in accordance with one embodiment of thepresent invention.

FIG. 3 is a cross-sectional diagram of a process chamber havingtemperature sensing components disposed therein, in accordance with oneembodiment of the present invention.

FIG. 4 is a cross-sectional diagram of a process chamber having atemperature sensing component disposed on the surface of a substratesupport, in accordance with one embodiment of the present invention.

FIG. 5 is a close-up cross-sectional view of a temperature sensingcomponent capable of sensing temperature on the surface of a substratesupport, in accordance with one embodiment of the present invention.

FIG. 6 is cross-sectional diagram of a process chamber having atemperature sensing component disposed therein, in accordance with oneembodiment of the present invention.

FIG. 7A is a cross-sectional view of a process chamber having atemperature sensing component disposed on the surface of a substratesupport, the substrate support also having a substrate disposed thereon,in accordance with one embodiment of the present invention.

FIG. 7B is a top view of a temperature sensing component capable ofsensing the temperature on the surface of a substrate support, inaccordance with one embodiment of the present invention.

FIG. 8 is a flow chart detailing a process to accurately measure the insitu process temperature, in accordance with one embodiment of thepresent invention.

FIG. 9A is a cross-sectional view of a temperature indication apparatus,in accordance with one embodiment of the present invention.

FIG. 9B is a cross-sectional view of a temperature indication apparatusindicating a phase change has occurred, in accordance with oneembodiment of the present invention.

DETAILED DESCRIPTION

The present invention, as illustrated by the following embodiments,provides the methods and structures that enable accurate in situtemperature measurement for processing substrates, and in particular,for fabricating semiconductors. The embodiments of the present inventioncan be easily integrated into process chambers for accurate in situtemperature measurement, thus improving overall process control, processmonitoring, and process repeatability without affecting processthroughput and yield. As should be appreciated, the present inventioncan be implemented in numerous ways, including a method or system. Insome instances, well known process operations and components have notbeen described in detail in order to avoid obscuring the presentinvention.

FIG. 1 shows a substrate process chamber system 100 according to oneembodiment of the present invention. Process chamber 102 includes asubstrate support 104, wherein the substrate support 104 has a pluralityof cavities 106, 116, 126, and 136. Each of the pluralities of cavities106, 116, 126, and 136 is suitably configured to hold one of a pluralityof materials 108, 118, 128, and 138 respectively therein. Each of aplurality of transparent covers 110, 120, 130, and 140 is suitablyconfigured to respectively cover an opening of the plurality of cavities106, 116, 126, and 136. Thus, each of the materials 108, 118, 128, and138 is contained in a respective one of the plurality of cavities 106,116, 126, and 136. Each of the materials 108, 118, 128, and 138 issubstantially sealed and isolated from the interior environment of theprocess chamber. Since the materials 108, 118, 128, and 138 are isolatedfrom the interior of the process chamber 102 they are also preventedfrom introducing any contaminants into the process chamber 102. In orderto properly seal and isolate the materials 108, 118, 128, and 138, thetransparent covers 110, 120, 130, and 140 are made from a suitablyrobust material to withstand the process conditions within the processchamber 102. One example of such a robust material is quartz.

Still referring to FIG. 1, one or more sensors 112 are configured in theprocess chamber 102 to monitor a phase change of each one of thematerials 108, 118, 128, and 138. For ease of illustration, FIG. 1 showsone sensor 112 configured in the process chamber 102. However, one ormore sensors 112 may be configured in the process chamber 102 to monitoreach one of the materials 108, 118, 128, and 138 for the respectivephase change of each of the materials. The phase change data gathered byone or more of the sensors 112 are transmitted to a monitor system 114.The monitor system 114 may include a system controller, which controlsall the components of the process chamber system 100 including theprocess operation of the process chamber 102. For example, the systemcontroller may control the operation of process chemicals into theprocess chamber 102, one or more heaters to heat the surfaces in theprocess chamber 102 to process a substrate, energy, e.g., RF, toenergize the chemicals in the process chamber 102 to initiate process,etc. The monitor system 114 processes the data, e.g., using a dataprocessing algorithm, and appropriately presents the analyzed data to auser by way of a user interface, e.g., a screen monitor.

As indicated, the one or more sensors 112 monitor the phase change ofthe materials 108, 118, 128, and 138 and record the phase change data aseach phase change occurs for each of the materials. The temperatureassociated with a phase change of a material, e.g., changing from asolid phase to a liquid phase, is a constant for a specific compositionof material at a given pressure. Thus, the phase change temperature fora known composition of material could be used as a reference to measureprocess temperature in the process chamber 102.

As shown in FIG. 1, the materials 108, 118, 128, and 138 arerespectively contained in one of the plurality of cavities 106, 116,126, and 136 that is incorporated in the substrate support 104. A phasechange of each of the materials 108, 118, 128, and 138 can be used tomonitor, measure, and characterize the process temperature of thesubstrate support 104. For example, as the process is initiated in theprocess chamber 102, the substrate support 104 is typically heated. As asufficient amount of heat energy is transferred from a heater to thesubstrate support 104, the materials 108, 118, 128, and 138 in therespective cavities 106, 116, 126, and 136 will begin to undergo phasechanges. The amount of heat energy that is transferred to the substratesupport can be measured and quantified over time by a process chambersystem controller. In the meantime, one or more sensors 112 aremonitoring the materials 108, 118, 128, and 138 for phase changes. As aphase change occurs, the location, e.g., contact surface, where thematerial is located has reached the phase change temperature associatedwith that material.

Since heat distribution across a surface is rarely uniform, embodimentsof the present invention are capable of determining the temperaturedistribution across a surface. For example, as illustrated in FIG. 1,materials 108, 118, 128, and 138 are disposed in the plurality ofcavities 106, 116, 126, and 136 located at different areas across thesurface of the substrate support 104. The temperature distributionacross the surface of the substrate support 104 can be determined aseach one of the materials 108, 118, 128, and 138 undergoes a phasechange. Materials 108, 118, 128, and 138 can be comprised of the samecomposition or materials 108, 118, 128, and 138 can be comprised ofdifferent compositions. If each of the materials 108, 118, 128, and 138is comprised of a known composition with a known phase changetemperature, the temperature distribution across the surface of thesubstrate support 104 can be determined over time as heat energy issupplied to the substrate support 104 and each material, over time,undergoes a phase change.

Since each of the materials 108, 118, 128, and 138 is respectivelysealed in each of the cavities 106, 116, 126, and 136 no significantloss of material would occur over time. Accordingly, the materials 108,118, 128, and 138 can be reused for repeated process cycles in theprocess chamber 102.

It is well known in chemical and material science that organic and someinorganic compounds exhibit very precise melting points, e.g., withinthe range of 0.1 or 0.2 degree Celsius. Some of these organic andinorganic compounds include naphthalene, salicylic acid, benzophenone,Cobalt (II) Nitrate, Aluminum benzoate, Aluminum acetate, Antimony (III)bromide, and Antimony (III) chloride.

Still referring to FIG. 1, the one or more sensors 112 are configured tosense the phase change of the materials 108, 118, 128, and 138. Thephase change of a material will cause a change in the refractive indexof the material. For some materials, the phase change will also cause achange in color of the material. As shown in FIG. 1, one or more sensors112 are configured to sense these or other changes that accompany aphase change of a material through the transparent covers 110, 120, 130,and 140. One example of a sensor 112 that is capable of sensing a phasechange as described is a laser spectrometer. The sensor 112 is connectedto communicate with the process chamber system controller. The sensor112 monitors the materials 108, 118, 128, and 138 and collects data forsensing phase changes. The sensor 112 sends the collected data to theprocess chamber system controller for processing. The process chambercontroller using a data processing algorithm processes the data andgenerates optical constant values that correspond to phase changetemperatures associated with the materials 108, 118, 128, and 138contained in the respective plurality of cavities 106, 116, 126, and136. The process chamber controller may be a separate unit locatedremotely from the monitor device 114. Alternatively, the process chambercontroller and the monitor device 114 may be integrated as one combinedunit. Regardless of the actual configuration of the process chambercontroller and the monitor device 114, the process chamber controllercommunicates with the monitor device 114 and monitor device 114 providesprocess temperature information to a user through a user interface,e.g., a screen monitor.

FIG. 2 shows a process chamber system 200 according to anotherembodiment of the present invention. Process chamber 202 includes asubstrate support 204, wherein the substrate support 204 has a pluralityof cavities 206 and 216. Each of the plurality of cavities 206 and 216is suitably configured to hold one of a plurality of materials 208 and218 respectively therein. Each of a plurality of transparent covers 210and 220 is suitably configured to respectively cover an opening of theplurality of cavities 206 and 216. Thus, each of the materials 208 and218 is contained in the respective one of plurality of cavities 208 and218, and each one of the materials 208 and 218 is substantial sealed andisolated. The transparent covers 210 and 220 are made from a suitablyrobust material to withstand the process conditions in the processchamber system 200. One example of such a robust material is quartz.

As shown in FIG. 2, one or more sensors 212 and 222 are configured inthe process chamber system 200 to monitor a phase change of each of thematerials 208 and 218. The phase change data gathered by the one or moresensors 212 and 222 are transmitted a monitor system 214. The monitorsystem 214 may include a system controller, which controls all thecomponents of the process chamber system 200 including the processoperation of the process chamber 202. For example, the system controllermay control the operation of process chemicals into the process chamber202, one or more heaters to heat the surfaces in the process chamber 202to process a substrate, energy, e.g., RF, microwave, etc., to energizethe chemicals in the process chamber 202 to initiate process, etc. Themonitor system 214 processes the data, e.g., using a data processingalgorithm, and appropriately presents the analyzed data to a user by wayof a user interface, e.g., a screen monitor.

Still referring to FIG. 2, the one or more sensors 212 and 222 monitorthe phase change of the materials 208 and 218 and record the phasechange data as each phase change occurs for each of the materials. Thetemperature associated with a phase change of a material, e.g., changingfrom a solid phase to a liquid phase, is a constant for a specificcomposition of material at a given pressure. Thus, the phase changetemperature for a known composition of material could be used as areference to measure process temperature in the process chamber 202,e.g., the surface temperature of the substrate support 204.

FIG. 3 shows a process chamber system 300 in accordance with anotherembodiment of the present invention. Process chamber 302 includes asubstrate support 304 and a plurality of cavities 336, 346, 356, and 366incorporated into the walls of the chamber 302. Each of a plurality ofmaterials 338, 348, 358, and 368 is respectively contained in one of theplurality of cavities 336, 346, 356, and 366 in the walls of thechamber, 302. Each of plurality of cavities 336, 346, 356, and 366 isrespectively sealed by one of a plurality of transparent covers 340,350, 360, and 370. One or more sensors 312 are configured to sense aphase change of each of the plurality of materials 338, 348, 358, and368 through the respective one of plurality of transparent covers 340,350, 360, and 370. Although one sensor 312 is shown in FIG. 3, one ormore sensors 312 can be configured in process chamber 302 to sense thephase change of each of the materials 308, 318, 328, 338, 348, 358, and368. In one implementation, the sensor 312 may be a laser spectrometer.The sensor 312 is connected to communicate with a process chamber systemcontroller. The sensor 312 sends data collected from monitoring thematerials 308, 318, 328, 338, 348, 358, and 368 to the process chambersystem controller for processing the data. The process chambercontroller using a data processing algorithm processes the data andgenerates optical constant values that correspond to phase changetemperatures associated with materials 308, 318, 328, 338, 348, 358, and368. The phase change temperature can be further processed and presentedto a user by way of a user interface, e.g., a screen monitor. Theinformation presented to a user could be in the form of temperaturedistribution plots, e.g., plots of temperature versus time distribution,temperature versus location distribution, etc.

FIG. 4 shows a cross-sectional view of a process chamber system 400 inaccordance with one embodiment of the present invention. In processchamber system 400, a substrate support 404 is disposed in processchamber 402. A temperature sensing test substrate 415 is disposed onsubstrate support 404. The temperature sensing test substrate 415comprises of a substrate layer 414 and a transparent layer 410. Aplurality of cavities 406, 426, and 436 are configured in thetransparent layer 410, wherein one of plurality of materials 408, 428,and 438 is respectively disposed in one of the plurality of cavities406, 426, and 436. The materials 408, 428, and 438 are in contact withthe substrate layer 414. The transparent layer 410 seals the materials408, 428, and 438 from the interior environment of the process chamber402, such that materials 408, 428, and 438 cannot induce anycontaminants into the interior environment of the process chamber 402.One or more sensors 412 are configured in process chamber 402 to sensephase changes of the materials 408, 428, and 438.

FIG. 5 shows a close-up cross-sectional view of the temperature sensingtest substrate 415 in accordance with an embodiment of the presentinvention. The temperature sensing test substrate 415 comprises of asubstrate layer 414 and a transparent layer 410. The transparent layer410 is configured with a plurality of cavities 406, 426, and 436. Eachof the cavities 406, 426 and 436 contains one of plurality of materials408, 428, and 438. The materials 408, 428, and 438 are in contact withthe substrate layer 414, such that at thermo-equilibrium, thetemperature of each of the materials 408, 428, and 438 is at the sametemperature as the substrate layer 414 at each contact surface area.

Referring back to FIG. 4, as the process is initiated in the processchamber 402, and the substrate support 404 is typically heated. Thetemperature sensing test substrate 415 may be used to determine thetemperature or heat distribution of a substrate that is being processedin process chamber 402.

As a sufficient amount of heat energy is transferred from a heater tothe substrate support 404, the substrate layer 414 of the temperaturesensing test substrate 415 is also heated by conduction and convection.The substrate layer 414 would simulate an actual substrate that is beingprocessed in the process chamber 402. Thus, the temperature of thesubstrate layer 414 would be similar to that of a substrate that isbeing processed in the process chamber 402. The materials 408, 428, and438 being in contact with the substrate layer 414 would be at the sametemperature as the substrate layer 414. As sufficient heat energy istransferred to materials 408, 428, and 438, phase change of thematerials would be initiated. One or more sensors 412 sense the phasechange of the materials 408, 428, and 438. The one or more sensors 412transmit the sensed data to a process chamber system controller toprocess the data and present the processed data to a user by way of auser interface, e.g., a screen monitor. The processed data presented toa user could be in the form of a temperature distribution plot of thesubstrate layer 414, which would be representative of a temperaturedistribution plot of a processed substrate.

FIG. 6 shows a temperature sensing component in accordance with oneembodiment of the present invention. Temperature sensing component 610is disposed in process chamber 602. The temperature sensing componentincludes a transparent shell 606 configured to contain a material 608.The transparent shell 606 is made of a robust material capable ofwithstanding the conditions (e.g., heat, pressure, RF energy, microwave,reactive plasma, etc.) within the process chamber 602 without anydegradation in its material properties. One example of such a robustmaterial is quartz. Material 608 is configured to be in contact with anysurface within the process chamber 602, while being sealed between thecontact surface within the process chamber 602 and the transparent shell606. A sensor 612 is located in the process chamber 602 to sense a phasechange of material 608 through the transparent shell 606. For example,sensor 612 may be a laser spectrometer. Material 608 may be an organicor an inorganic compound having a very precise melting point, e.g.,melting point within the range of 0.1 or 0.2 degree Celsius. Some ofthese organic and inorganic compounds include naphthalene, salicylicacid, benzophenone, Cobalt (II) Nitrate, Aluminum benzoate, Aluminumacetate, Antimony (III) bromide, and Antimony (III) chloride. For easeof illustration and discussion only one temperature sensing component610 and sensor 612 are shown disposed in process chamber 602 in FIG. 6,however, within the scope of the present invention, any number oftemperature sensing components and sensors may be implemented in processchamber 602.

As process is initiated in the process chamber 602, the chamber surfacesare also heated. The chamber surfaces could be heated in many differentways. The chamber surfaces could be heated by a circulating fluid, aheater, or any other appropriate means. The embodiments of the presentinvention provide the method and apparatus for accurately measuring thein situ process temperature.

The material 608 being in contact with a surface within the processchamber 602 would be at the same temperature as the contact surface. Asa sufficient amount of heat energy is transferred from the contactsurface to material 608, material 608 will undergo a phase change.Sensor 612 senses the phase change and transmits the phase change datato a process chamber system controller. The process chamber systemcontroller processes the phase change data and provides the processedphase change data to a user by way of a user interface, e.g., a screenmonitor. The processed phase change data could be in the form oftemperature distribution plots.

FIG. 7A shows another temperature sensing component in accordance withone embodiment of the present invention. A temperature sensing component710 is disposed on a substrate support 704 in process chamber 702.Substrate 714 is also disposed on substrate support 704. Temperaturesensing component 710 may have a plurality of cavities. As shown in FIG.7A, materials 718 and 728 are respectively contained in two of thecavities in temperature sensing component 710. Materials 718 and 728 arein contact with substrate support 704. Sensors 712 and 722 areconfigured to sense phase change of materials 718 and 728. Although FIG.7A shows sensors 712 and 722 configured to sense phase change ofmaterials 718 and 728, any number of sensors can be used to sense thephase change of materials 718 and 728. For example, one sensor may beconfigured to sense phase change for any number of materials containedin the temperature sensing component 710.

FIG. 7B show a top view of temperature sensing component 710 andsubstrate 714. The temperature sensing component 710, in accordance withone embodiment of the present invention, enables simultaneoustemperature sensing and substrates processing at the same time. As aprocess is initiated in process chamber 702, the substrate support 704is typically heated to facilitate processing of substrate 714. As asufficient amount of heat energy is transferred from a heater to thesubstrate support 704 to heat the substrate 714 for processing, thematerials 718, 728, 738, and 748 are also heated. The materials 718,728, 738, and 748 are selected for having very precise melting points,e.g., within the range of 0.1 or 0.2 degree Celsius. As is well known,the temperature associated with a phase change of a material is aconstant for a specific composition of material, therefore, the phasechange temperature for materials 718, 728, 738, and 748 may be used as areference temperature to control and monitor the process temperature forsubstrate 714.

Sensors 712 and 722 configured to sense phase change of materials 718,728, 738, and 748 transmit phase change data to a process chamber systemcontroller to control the process temperature, e.g., the surfacetemperature of the substrate, to prevent temperature variations thatwould affect process outcomes, e.g., critical dimensions of devicefeatures in semiconductors. In addition, the process chamber systemcontroller could provide real-time processed phase change data to a userby way of a user interface, e.g., screen monitor. The processed phasechange data could be temperature distribution plots.

FIG. 8 shows a flowchart detailing a method of accurately measuring insitu process temperature in accordance with one embodiment of thepresent invention. The method begins with operation 800 by placing oneor more temperature sensing components into a process chamber. Thetemperature sensing components may be any of the temperature sensingcomponents discussed according to the various embodiments of the presentinvention. Then, a process is initiated in the process chamber inoperation 802. The initiated process eventually causes a phase change toeach of the materials in the respective temperature sensing componentsin operation 804. One or more sensors in the process chamber detect thephase changes of the materials in the respective temperature sensingcomponents in operation 806. The process chamber system controllerprocesses the phase change data for each of the materials in operation808. A temperature associated with a respective phase change of eachmaterial is determined in operation 810, and in operation 812, theassociated temperatures are recorded. It should be appreciated that thetemperatures associated with the phase change for any of the materialslisted herein are well documented. For example, naphthalene has amelting temperature of 80.5 degree Celsius, salicylic acid has a meltingtemperature of 135 degree Celsius, benzophenone has a meltingtemperature of 48.1 degree Celsius, Cobalt (II) Nitrate has a meltingtemperature of 55 degree Celsius, Aluminum benzoate has a meltingtemperature of 198 degree Celsius, Aluminum acetate has a meltingtemperature of 114 degree Celsius, Antimony (III) bromide has a meltingtemperature of 96.6 degree Celsius, and Antimony (III) chloride has amelting temperature of 73.4 degree Celsius.

FIG. 9A shows a temperature indicating apparatus in accordance withanother embodiment of the present invention. FIG. 9A shows thetemperature indicating apparatus 904 having a cavity 906. Cavity 906 hasat least two chambers, for example, a first chamber 912 and a secondchamber 914. In this embodiment, a material 908 is disposed in the firstchamber 912. A cover 910 seals the cavity 906. The cover 910 may be atransparent cover, so that the temperature indicating apparatus 904 maybe used to indicate in situ process temperature as discussed above.Similar to the temperature sensing components as previously discussedfor other embodiments of the present invention, the temperatureindicating apparatus 904 may be disposed in a processor chamber and thephase change of the material 908 may be sensed by a sensor configured tosense a phase change of the material 908 through the cover 910.

FIG. 9B shows a temperature indicating apparatus in accordance with oneembodiment of the present invention in which material 908 has undergonea phase change. As shown in FIG. 9B, the material 908 is transferredfrom the first chamber 912 to the second chamber 914 as the material 908changed from one phase to another phase, e.g., solid phase to liquidphase or vice versa. The temperature indicating apparatus 904 is capableof indicating whether a phase change temperature associated with thematerial 908 was reach by observing the spatial location of the material908 in the cavity 906, i.e., whether the material is contained in thefirst chamber 912 or the second chamber 914. Accordingly, thetemperature indicating apparatus 904 may be observed after a processcycle is completed to verify that a process temperature has reached atemperature associated with the phase change of material 908 at somepoint in the process as the process recipe was executed. In oneembodiment of the present invention, cover 910 may not be a transparentcover. For example, where the temperature indication apparatus is usedas a spatial indicator, it is not necessary to have a transparent cover.

Although a few embodiments of the present invention have been describedin detail herein, it should be understood, by those of ordinary skill,that the present invention may be embodied in many other specific formswithout departing from the spirit or scope of the invention. Therefore,the present examples and embodiments are to be considered asillustrative and not restrictive, and the invention is not to be limitedto the details provided therein, but may be modified and practicedwithin the scope of the appended claims.

1. A semiconductor process chamber, comprising: a temperature sensingcomponent disposed within a wall defining the semiconductor processchamber, wherein the temperature sensing component has a cavity; atransparent cover disposed over an opening of the cavity; a materialdisposed within the cavity of the temperature sensing component; and asensor disposed within the semiconductor process chamber and having aline of sight to the material, the sensor configured to sense a phasechange of the material through the transparent cover.
 2. The processchamber of claim 1, wherein the phase change includes one of changingfrom a solid phase to a liquid phase or changing from a liquid phase toa solid phase.
 3. The process chamber of claim 1, wherein the materialis one of an organic or an inorganic compound.
 4. The process chamber ofclaim 3, wherein the organic compound is selected from the groupconsisting of naphthalene, salicylic acid, and benzophenone, and theinorganic compound is selected from the group consisting of Cobalt (II)Nitrate, Aluminum benzoate, Aluminum acetate, Antimony (III) bromide,and Antimony (III) chloride.
 5. The process chamber of claim 1, whereinthe cavity has at least two chambers and the material within the cavityis transferred from a first chamber to a second empty chamber as thematerial undergoes the phase change.
 6. The process chamber of claim 1,wherein the sensor is a laser spectrometer, and the transparent cover iscomposed of quartz.
 7. A method of characterizing temperaturedistribution in a process chamber, the method comprising: locating atemperature sensing component having an embedded material within a wallof the semiconductor process chamber; initiating a process operationwithin the semiconductor process chamber; detecting a phase change ofthe embedded material within the wall of the process chamber through asensor disposed within the semiconductor process chamber; and recordinga temperature associated with the phase change.
 8. The method of claim7, further comprising: placing another temperature sensing componentinto a substrate support of the process semiconductor chamber.
 9. Themethod of claim 7, wherein the wall is a sidewall of the semiconductorprocess chamber.
 10. The method of claim 7, wherein the phase changeincludes one of changing from a solid phase to a liquid phase orchanging from a liquid phase to a solid phase and wherein the phasechange causes movement from a first chamber to a second empty chamberwithin the temperature sensing component.
 11. The method of claim 7,further comprising: covering the embedded material with a transparentcover.